01 - Preheat the oven to 425°F. Line a baking sheet with parchment paper.
02 - Spread the cauliflower florets on the prepared baking sheet. Drizzle with olive oil and sprinkle with a pinch of salt and pepper. Toss thoroughly until evenly coated.
03 - Roast the cauliflower for 25 to 30 minutes, flipping halfway through, until the florets are golden brown and fork-tender.
04 - While the cauliflower roasts, whisk together the mayonnaise, sour cream, lime juice, lime zest, minced garlic, salt, and pepper in a large mixing bowl until smooth and well combined.
05 - Transfer the roasted cauliflower to the bowl with the dressing and toss gently until every floret is evenly coated.
06 - Arrange the dressed cauliflower on a serving platter. Finish with crumbled cotija cheese, chili powder, smoked paprika if using, chopped cilantro, and sliced scallions. Serve immediately with lime wedges alongside.